Signoes to the spencer electrical co



(No Model.) 7

J. H. SPENCER 8; M. S. KEYES.

TELEPHONE TRANSMITTER.

No. 596.834. Patented Jan. 4, 1898.

T w/ NESSES: gvmmfls .y to V B) I g t r 1- 1% ATTORNEYS UNITED STATES -.PATnNr @rrrcn.

JAMES H. SPENCER AND MALCOLM S. KEYES, OF NElV YORK, N. Y., AS-

SIGNORS TO THE SPENCER ELECTRICAL 00., OF SAME PLACE.

TELEPHONE-TRANSMiTTER.

SPECIFICATION forming part of Letters Patent No. 596,834, dated January 4, 1898.

Application filed January 14, 1897. Serial No. 619,233. (No model.)

To (0Z1. 1072/0721, it may concern.-

Be it known that we, J AMES H. SPENCER and MALCOLM S. KEYES, of New York city, in the county and State of New York, have invented certain new and useful Improvements in Tlelephone-Transmitters, of which the following is a full, clear, andexact description.

The object of the invention is to provide certain new and useful improvements in telephone-transmitters whereby the loose granulated carbon is held in position by the buttons to insure a proper transmission of the sounds, and the distance between the buttons can be readily increased or diminished according to the intended use and surroundings of the instrument.

The invention consists of certain parts and details and combinations of the same, as will be fully described hereinafter and then pointed out in the claims.

Reference is to be had to the aceompanyin g drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a sectional side elevation of the improvement. Fig. 2 isa transverse section of the same on the line 2 2 of Fig. 1. Fig. 3 is a perspective view of the diaphragm and parts held on the inside thereof. Fig. 4; is a perspective view of the adjustable button, and Fig. 5 is a sectional side elevation of a modified form of button.

The telephone-transmitter is provided with a suitably-constructed casing A, having an annular rest A for the ring B, of rubber or other material, and inclosing the outer edge of the diaphragm C, held to its seat by arms D, engaging the ring 13, as shown in Fig. 2. On the rear face of the diaphragm is secured a button E, made of carbon or like material, and opposite to which is arranged a like button E, fitted into a cap E provided with a stem E fitted to slide longitudinally in a bearing F, formed on a barF, secured to lugs A, projecting from the casing A. The rod or stem E is adapted to be fastened in place in the bearing F by a set-screw E, which when loosened permits of adjusting the button E, so as to increase or diminish the distance between the opposing faces of the buttons E and E. The opposing faces of the buttons are roughened,

and forthis purpose are provided with grooves E preferably made concentric, to insure a large contacting-surface for the transmitting device held loosely between the two buttons. This transmitting device consists, preferably, of a disk G, of cork or other material, and in which are set or formed pins G, preferably of German silver, and projecting from the faces of the disk and in contact with the faces of the buttons E and E. The pins G may be straight, as indicated in Fig. 1, or formed with spiral coils (see Fig. 5) to insure greater resistance, if desired. Instead of the abovementioned disk and its pin we may use the ordinary loose granulated carbon or German silver in granulatedform.

In order to prevent the loose transmitting device from working out between the buttons, the latter are inclosed by a wrapper H, made of a fabric or like flexible material, and wound peripherally around the two buttons, as plainly indicated in Fig. 1. The wrapper H is provided at or near its middle and between the adjacent edges of the buttons with openings 1 to render the wrapper veryflexible, so as to offer as little resistance as possible to the vibrations of the buttons.

The electric wires are connected in the usual manner to thediaphragm C and bar F. A cap F formed on the bar F, serves to protect the buttons E and E, as indicated in Fig. 1. In order to protect the diaphragm C, a perforated disk, plate, screen, or like device I is placed in front of said diaphragm next to the mouthpiece.

Having thus described our invention, We claim as new and desire to secure by Letters Patent 1. A telephone-transmitter, provided with buttons, and granulated German silver held between the buttons, substantially as shown and described.

2. A telephone-transinitter provided with buttons, and a disk held between the buttons and having pins projecting from its faces to engage the faces of the buttons, substantially as shown and described.

3. A telephone-transmitter provided with buttons having their opposing faces formed with concentric grooves, and a transmitting device held loosely between the buttons and comprising a disk having pins projecting from.

its faces to engage the faces of the buttons, substantially as shown and described.

41. A telephone-transmitter, comprising a diaphragm, a button secured thereto, a second button held longitudinally adjustable relatively to said fixed button, the opposing faces of the said buttons being roughened and grooved, and a disk held loosely between the buttons and having pins projecting from its faces to engage the faces of the buttons, substantially as shown and described.

5. A telephone-transmitter provided with buttons, a disk held between the buttons and having pins projecting from its faces to engage thefaces of the buttons, and a wrapper made of flexible material and peripherally inclosing the buttons, substantially as shown and described.

6. A telephone-trailsmitter, comprising a casing provided with a diaphragm, the said casing having oppositely-arranged rearwardly-extending lugs, a bar secured at its ends to the said lugs and having a central rearwardlyextending projection provided with an opening and forming a bearing, the said bar being also provided with a forwardly-proj ectin g cap, a button secured to the diaphragm, a cup provided with a stem adjustable in the said bearing in the bar, means for holding the said stem rigidly in said bearing, and a second button fitted into said cup, the forwardly-projecting cap on the said bar peripherally inclosing said buttons, substantially as shown and described.

7. A telephone-transmitter, comprising a casing, a diaphragm, a ringinclosin g the outer edge of said diaphragm, the said casing having an annular rest for the said ring, curved arms secured to the casing and engaging the said ring to hold the diaphragm to its seat. a button secured to the rear face of the diaphragm, a second button adapted to be rigidly supported from the back of the casing, loose transmitting material between the buttons, at

flexible wrapper wound peripherally around the two buttons and provided at or near its middle and between the adjacent edges of the buttons with openings arranged at intervals. and a forwardly projecting cap on the back of the casing loosely inclosing the buttons and wrapper, substantially as shown and described.

8. A telephone-transmitter, comprising a casing provided with a diaphragm, the back of said casing having a central rearwardlyextending projection provided with an opening and forming a bearing, the back of said casing being also provided with a forwardlyprojecting cap, a button secured to the diaphragm, a cup provided with a stem adj ustable in the said bearing in the back of the casing, means for holding the said stem rigidly in said bearing, a second button fitted into said cap, and a wrapper made of flexible material and peripherally inclosing the buttons,theforwardly-projecting cap 011 the back of the casing peripherally inclosing the buttons and wrapper, substantially as shown and described.

JAMES H. SPENCER. MALCOLM S. KEYES. Witnesses:

O. L. CHILD, EMILE WALLI. 

